Using Marijuana to Treat Pain? A Pill May Outlast a Puff

MONDAY, April 22 (HealthDay News) -- A pill may work as well as
a puff when it comes to using marijuana to treat pain, according to
a small but carefully controlled new study. Pain relief from pills
may last longer, however, and may not leave people feeling as high
as they do after they smoke the drug.

Medical marijuana is now legal in 18 states and the District of
Columbia, according to the nonprofit group ProCon.org. Surveys show
pain is one of the main reasons doctors prescribe it. But studies
testing marijuana as a pain reliever have had mixed results. Some
have shown that it works as well as mild opioid (narcotic) pain
relievers like codeine, while others have indicated that the drug
might actually make pain worse.

To learn more, researchers at the Substance Use Research Center
of the New York State Psychiatric Institute pitted two strengths of
smoked marijuana against two strengths of the drug dronabinol,
which contains tetrahydrocannabinol, or THC, the same active
ingredient as in marijuana plants.

Dronabinol has been FDA-approved since 1985 to treat the nausea
and loss of appetite that commonly afflict patients with cancer and
AIDS. Less is known about its effects on pain.

For the government-sponsored study, researchers recruited 30
healthy, pain-free men and women who were already regular marijuana
smokers.

During five experimental sessions, participants took a capsule
and then 45 minutes later smoked a marijuana cigarette. The
capsules contained either an inactive placebo, or 10 milligrams or
20 milligrams of dronabinol. The cigarettes were specially made by
the U.S. National Institute on Drug Abuse, which funded the study.
Cigarettes were standardized to contain marijuana with no THC, a
low dose of the drug or a higher dose.

People in the study never knew whether they were smoking or
swallowing the drug or how strong the dose was. Researchers made
sure they never got a double hit of the drug during the same
session.

The testing days were spaced at least two days apart, and
participants were asked to refrain from smoking the night before
their lab visits.

Several times during the sessions, researchers had each person
place their hands in a water bath kept just above freezing
temperatures. They measured how long it took study participants to
feel pain and then how long they were able to tolerate the pain
before they yanked their hand out of the water. Participants also
answered questions about how intensely they felt the pain during
the experiments and how high they felt.

When researchers tallied their data, they found that both the
smoked drug and the pill were about equally effective at
controlling pain.

After smoking the strongest cigarettes or taking the highest
strength of the pill, it took people an average of about 12 to 13
seconds longer to report feeling pain from the cold water compared
to when they took the placebos. Both forms of the drug also
significantly increased pain tolerance, the amount of time a person
was able to stand the pain before they pulled their hand out of the
cold water.

Additionally, study participants reported that their pain was
decreased after they smoked either strength of marijuana cigarette
and after they took the highest strength of the dronabinol
capsules.

The biggest differences between the puffs and the pills had to
do with how long it took the drug to work and how high people felt
after they used it.

Researchers found that pain relief peaked about 15 minutes after
people smoked the marijuana and wore off relatively quickly. The
pills took longer to work, but the pain relief lasted three to four
hours.

Participants also reported feeling much higher after smoking the
drug compared to when they swallowed it. The feeling of being high
usually outlasted any pain relief.

"If you think about it, if you're someone who's dealing with chronic pain, you're going to have to be smoking several times a day, and for a lot of people that would not be feasible," said study author Ziva Cooper, an assistant professor of clinical neurobiology at Columbia University, in New York City.

Cooper also noted that swallowing a pill might be a safer way to
take the drug than smoking it. There's some concern, though scant
evidence, that smoking marijuana might increase the risk for lung
cancer.

Dr. Gary Reisfield, an assistant professor of addiction medicine
and chief of pain management services at the University of Florida
College of Medicine, in Gainesville, praised the study for being
"well-conceived and meticulously designed."

He said the research should help doctors and patients better
understand how to use the drug.

"Smoked cannabis works faster, but oral THC works longer. For the management of chronic pain and other symptoms, the duration of action is often more important than the rapidity of onset. It is more convenient, and often more desirable, to administer a medication two or three times daily rather [than] every two or three hours," said Reisfield, who was not involved in the research.

When it comes to price, it costs somewhat more to swallow
average doses of the drug than to smoke it, according to
ProCon.org. At an average dose of two joints a day, it costs about
$514 a month to smoke marijuana. The usual dose of dronabinol,
which is the generic form of the drug Marinol, costs about $678 a
month.

But dronabinol is often covered by insurance, so an insured
patient would pay far less, between $15 and $30 each month for
their prescription.

The study was published April 22 in the journal
Neuropsychopharmacology.

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.